main/postmarketos-mkinitfs: mount /sysroot/boot (MR 1398)

Mount the boot partition at /sysroot/boot and keep it mounted, when
running the switch_root command. This way, OpenRC doesn't need to mount
it and possibly use the wrong partition. The OpenRC service does not use
the same logic to find the boot partition, in particular it does not
support the pmos_boot kernel parameter.

While at it, print the mountpoint and read-only/read-write arguments in
the mounting log message for both root and boot.

Fixes: #664

main/postmarketos-mkinitfs/APKBUILD

@@ -1,5 +1,5 @@
 pkgname=postmarketos-mkinitfs
-pkgver=0.12.2
+pkgver=0.12.3
 pkgrel=0
 pkgdesc="Tool to generate initramfs images for postmarketOS"
 url="https://postmarketos.org"
@@ -39,8 +39,8 @@ check() {
 }
 
 sha512sums="5037cb7285bb7c0c40ca9e6df332d882ef9a8b379756c785f921e062dab1b7e7f3139d00897f69323a916d709ced4297fea8cbd3a13ebae575b873ec9e2cbfae  00-default.modules
-1d49db8a48ad513cc548b8a0ea23cc64518e71c93863155b4e9d2271fb46090506331c03d6955d693c8568c248ecc76b218efe4a6f6bba57c41c5f6d775dc61b  init.sh.in
-ae7a7538f62616b9ee8b56b39531782c7d61ecb1679677d6bbe0f5e3ca228941bf2f340fead1d1abd971df30ff3059428d8f759660f53ec946ad8026e0e59c4b  init_functions.sh
+995b4d15e6b248d55d53221ec52674e62d74f0be539ac2ab26d4279544e2bece7aa58810dd831e1b2f08f0520fc9a8dff3ad4df52a46ef73f61e462f74f68c48  init.sh.in
+683b1784cc6572717dd805caabea38fac1780b03ff3540b888aab4fd91ccae404634874e6c9fa39f723186821a849844c6df1235bdcbf47b2de6b7f483c42178  init_functions.sh
 7201d4640a3e9ead8a47ffd9916b068476b7d950760a84c37e02268c942d49896bc986da6bdee27e832639c90775354d68046a6475205d8d1da995b068120d8f  mkinitfs.sh
 5105fcc5f2094009937b378c8d383270f4fcd0133d0e60268806a7d09966613f4ebfa93d7e1b90b5d83d0c5b1664a0b3fc7562e52cc1e0ca6cd54ff442b03e84  mkinitfs_functions.sh
 c7a3c33daeb12b33ac72207191941c4d634f15c22958273b52af381a70ebaba1d3a9299483f0c447d9e66c560151fe7b9588bb4bbef2c8914f83185984ee4622  mkinitfs_test.sh"

main/postmarketos-mkinitfs/init.sh.in

@@ -35,7 +35,7 @@ show_splash /splash-loading.ppm.gz
 setup_usb_network
 start_udhcpd
 
-mount_boot_partition
+mount_boot_partition /boot
 extract_initramfs_extra @INITRAMFS_EXTRA@
 start_charging_mode
 wait_root_partition
@@ -44,12 +44,15 @@ unlock_root_partition
 resize_root_filesystem
 mount_root_partition
 
+# Mount boot partition into sysroot, so OpenRC doesn't need to do it (#664)
+umount /boot
+mount_boot_partition /sysroot/boot "rw"
+
 init="/sbin/init"
 setup_bootchart2
 
 # Switch root
 killall telnetd mdev msm-fb-refresher 2>/dev/null
-umount /boot
 umount /proc
 umount /sys
 umount /dev/pts

main/postmarketos-mkinitfs/init_functions.sh

@@ -164,6 +164,11 @@ find_boot_partition() {
 	findfs LABEL="pmOS_boot"
 }
 
+# $1: path
+# $2: set to "rw" for read-write
+# Mount the boot partition. It gets mounted twice, first at /boot (ro), then at
+# /sysroot/boot (rw), after root has been mounted at /sysroot, so we can
+# switch_root to /sysroot and have the boot partition properly mounted.
 mount_boot_partition() {
 	partition=$(find_boot_partition)
 	if [ -z "$partition" ]; then
@@ -171,8 +176,17 @@ mount_boot_partition() {
 		show_splash /splash-noboot.ppm.gz
 		loop_forever
 	fi
-	echo "Mount boot partition ($partition)"
-	mount -r "$partition" /boot
+
+	if [ "$2" = "rw" ]; then
+		mount_opts=""
+		echo "Mount boot partition ($partition) to $1 (read-write)"
+	else
+		mount_opts="-o ro"
+		echo "Mount boot partition ($partition) to $1 (read-only)"
+	fi
+
+	# shellcheck disable=SC2086
+	mount $mount_opts "$partition" "$1"
 }
 
 # $1: initramfs-extra path
@@ -257,7 +271,7 @@ resize_root_filesystem() {
 
 mount_root_partition() {
 	partition="$(find_root_partition)"
-	echo "Mount root partition ($partition)"
+	echo "Mount root partition ($partition) to /sysroot (read-only)"
 	mount -t ext4 -o ro "$partition" /sysroot
 	if ! [ -e /sysroot/usr ]; then
 		echo "ERROR: unable to mount root partition!"